1. Field of the Invention
The present invention relates to a seismic alarm device for vehicles in which an alarm signal is generated when an earthquake is detected based on output signals from acceleration detector elements which are mounted at various points on a vehicle.
2. Description of the Prior Art
Conventionally, a device for detecting an earthquake and generating an alarm signal has been employed in various fields. For example, there is a device in which an acceleration detector element employing a pendulum or consisting of a piezoelectric element or strain gage is mounted on a stationary object, and an alarm signal is generated when such element vibrates at a value higher than a predetermined vibration value or outputs a signal which exceeds a predetermined value.
However, all such are mounted on a stationary object, and there has been no example where they are mounted on a moving object such as a vehicle which is subject to various types of pitching according to conditions of the road surface on which it is moving.
There have been considerable vehicle accidents causing from damages of roads due to a huge earthquake. If a device were able to generate an alarm signal as soon as an earthquake occurs, such vehicle accidents could have been prevented from causing by stopping the vehicle with a seismic alarm device.
It is therefore an object of this invention to provide a vehicle-mounted seismic alarm device for vehicles being capable of detecting a difference between the jolts of the vehicle caused by an earthquake and those by vehicle movement, and generating an alarm signal in case of the earthquake.